Scarfing machine



July 27, 1954 G. B. UPHAM SCARFING MACHINE 2 Sheets-Sheet 1 Filed May11, 1953 G/LBERT 5. 01 6 6744,

INVENTOR.

July 1 G.B.UP

SCARFING MACHINE Filed M y 1953 2 Sheets-Sheet 2 4 I l V. l5

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Patented July 27, 1954 UNITED STATES ENJT' OFFICE Summerbell RoofStructures, Los Califl, a corporation of California Angeles,

Application May 11, 1953, Serial No. 354,123

5 Claims.

This invention-relates to a scarfing machine for forming oppositelydisposed scarfs on the end of Y a wooden structural element.

Explanatory ofthe present invention, the use of oppositely disposedscarfs on the ends of are used are disclosed-in United States LettersPatent No. 2,409,383 to A. V. Pedersen issued October 15, 1946 and2,478,421issued August 9, 1949110 A. V. Pedersen.

Anobject of thepresent invention is to provide a machine which willenable thesedouble scarfs to bequickly and accurately formed on the endof a wooden-board or timber. In the usual situation-theslope of eachscarf is in the neighborhood-of-one to-ten or one to twelve, so that theend of the scarf tapersto athin edge. In cutting such scarfs on-theendof the board or timber, it is desirable to be able to cut the woodrapidly but at the same time avoid damagingor splitting the wood at suchthin edge. It is also essential that the scarfed tongues mutually meetin the same vertical plane so that a tight joint may besecured betweenthe structural elements when they are mutually assembled in endto-endrelationship. It. is therefore a further object of the present inventionto provide a machine which will satisfactorily meet these requirements.

With the foregoing and other objects in view, which will. be mademanifest in the following detailed description and .specifically pointedout inthe appended claims, reference is had to the accompanying drawingsfor an.illustrative embodiment ofthe invention, wherein:

Figure 1 is a view in side elevation of the scarfing'machine embodyingthe presentinvention, parts being broken away and shown in verticalsection;

Fig. 2 is a partial view illustrating details of one of the routersforming a part of the machine; v

Fig. 3 is a partial view taken substantially upon the line 3-3 upon Fig.1 to illustrate the stop, and hold down forming a part ofthe machine,the stop being shown in its elevated position;

Fig. 4 is a view similar to Fig. 3 but illustrating the stop in itsretracted position;

Fig. 5 is a partial view taken substantially upon the line 5-5 upon Fig.2;

Fig. 6 is a partial view illustrating the scarfs as having beenformed'on a structural element; and

Fig. 7 is a partial view in perspective illustrating the scarfed end ofthe structural element.

Referring to the accompanying drawings wherein similar referencecharacters designate similar parts throughout, the end product producedby the scarfing machine herein disclosed s illustrated in Fig. '7wherein a board or timber It has two oppositely disposed scarfs formedthereon dividing the endof the board into two tongues II and i2. Thetongue-ll is scarfed on its underside, as indicated at l3, while thetongue I2 is scarfed on its upper side, as indicated at M. These tonguesare defined from each other by sides l5 and it which are arranged in thesame vertical plane. Usually this plane is locatedon the longitudinalcenter line of the board or timber l0, although this is not necessarilyso.

The scarfing machine embodying the present invention comprises asuitable frame 20 on which there is a suitable support 2| having alateral guide 22 against which the board It may be positioned. On theframe 20 there is a rocker shaft 23 carrying a stop 24 that is capableof swinging upwardly beyond the. end of the support 2| so as to beengaged by the end of the board. Thus. when the board In is pressedlaterally against. the guide 22 and has its end engaging the stop 24,the board will be accurately positionedwithrelation to the cutters ofthe routers, hereinafter to .be described.

The rocker shaft 23 carries a crank 25 havinga pin andslot connection.26 with the piston rod of a piston, not shown, which is reciprocablewithin a pneumatic cylinder 21 that is supplied with. air pressure, suchas through a hose or conduit 28. Thus, when. thepiston within thecylinder 21 is actuated, theirocker shaft 23 may be partially rotated toswing thestop 24 downwardly from the position shown in Figs. 1 and 3into the positionshown inFig. 4. On the other hand, when the airpressure is supplied to the opposite end of the cylinder 21, the pistonis moved in the reverse direction, swinging the stopfrom thepositionshownin Fig. 4 into the position shown in Fig. 3, so as to be engageableby. a subsequent board.

As will be noted from an inspection of Fig. 4, the support 2| is cutaway, as indicated at 29,

for a distance from the end of the support somewhat greater than thelength of the scarf that is to be cut so that at the end of the board Ionly a portion of the underside of the board is actually engaging andresting on the support.

Over the support 2| there is a hold down 30 suspended by means ofsprings 3| and 32 from brackets 33. These brackets, in turn, supportpneumatic cylinders 34 and 35 within which there are reciprocablepistons. The rod of the piston in the cylinder 35 is directly connectedto the hold down 30' but the rod of the piston in the cylinder 34 isequipped with a presser foot 35 engageable with the forward end of thehold down. This presser foot is urged into its uppermost position by atension spring 31. The pneumatic cylinders 21, 34 and 35 may all beconnected to the same source of supply of compressed air so that afterthe board Ill has been positioned on the support against the guide 22and against the stop 24, on supplying air to the pneumatic cylinders thestop 24 may be swung downwardly into the position shown in Fig. 4, and,simultaneously, the hold down 36 will be pressed downwardly intoengagement with the top of the board to clamp it against the support.The hold down is cut away, as indicated at 38, similarly to the cut awayportion 29, so as to avoid any interference with the cutters of therouters.

On the frame 20 there are two rails 39 and 40 which provide ways thatmutually diverge with relation to each other in a directionlongitudinally of the board it. In the preferred arrangement, the rail39 is pivotally mounted on the frame, as at M, and the rail 40 ispivotally mounted on the frame, as indicated at 42. This pivotalmounting enables these ways to be adjusted in cutting scarfs havingdifferent slopes. The rails are maintained in adjusted positions bymeans of eye bolts 43 which are pivotally mounted on the frame 28 andwhich extend through ears on the rails 38 and 40 respectively. Byadjusting the nuts on these eye bolts, the tilt of each of the rails canbe varied, and after the adjustment has been made, the rails may beeffectively locked in adjusted positions. On the upper rail there isslidably or movably mounted a carriage 44 which carries an electricmotor 45 that drives a spindle 46 on which a routing cutter 41 ismounted. In a similar manher, a carriage 48 is slidably or movablymounted on the lower rail 39, and carries an electric motor .9 thatdrives a spindle 50 on which a routing cutter 5i is rotatably mounted.

A chain 52 is connected to the carriage 48 and passes over a sprocket 53at the end of the rail 39. From this sprocket the chain passes oversprockets 54, 55, and E6, and is connected to the carriage 44. Anotherchain 5'! is connected to the carriage 4d and is trained over a sprocket58. This chain is trained over sprocket 59 and a sprocket behind thesprocket 55 and over sprocket (it. In association with the carriage 48there is a pneumatic cylinder Bi within which there is a piston 62, therod of which is connected to the carriage 48. The ends of this pneumaticcylinder are supplied with .air under pressure by conduits or hoses 63.With this arrangement it will be noted that if air is supplied to thepneumatic cylinder 6! to force the piston 62 toward the right as viewedin Fig. 1, the chain connections afiorded by the chains 52 and 57 causeboth carriages 44 and 48 to simultaneously advance toward the board it.Conversely if air pressure is supplied to the opposite end of thecylinder Bl to force the piston 62 toward the left as viewed in Fig. 1,

both carriages 44 and at will be caused to simultaneously recede orretract away from the board l0.

As will be observed from Fig. 1, the spindle 50 is disposed somewhat inadvance of the spindle 46, which enables the cutting blades on therouting cutters 41 and ill to cut to the same vertical plane,represented by the line P on Fig. 5, without danger of interferencebetween the blades.

Behind the routers there may be a conduit 6 through which air is drawnso as to carry away cuttings cut from the board by the router cutters.

It will be appreciated that when a board has been positioned on thesupport and is clamped thereon by the hold down 36 and the stop 24 hasbeen swung downwardly into the position shown in Fig. 4 that when air issupplied to the air cylinders 6|, both router cutters 41 and 5! will beadvanced towards the end of the board. However, these router cutters arerouting in different planes and are caused to advance toward the end ofthe board upon divergent paths due to the divergency of the rails 39 and48'. The cutter 41 will, consequently, cut the scarf E4 on the tongue i2up to the vertical side It. Simultaneously, the router cutter 5| willcut the scarf it on the tongue ii up to the side it. In this manneroppositely disposed scarfed tongues may be cut in a single operation onthe end of the board. These tongues will be accurately formed withoutdanger of splitting or otherwise damaging the thin ends of the tongues.Structural elements whose ends have been formed in this manner may bemutually assembled together and when glue is applied to the scariedfaces l3 and M, a very sturdy and highly satisfactory joint betweenadjoining structural elements can be obtained.

When the cutting operation has been completed and the routers have beenreturned to their initial positions, as shown in Fig. 1, the air may bereversed in the cylinders El, 35, and 35, causing the hold down 38 to belifted to release the board that has been scaried and causing the returnof the stop 24 so that it may function to properly locate a succeedingboard positioned on the support 2!.

As will be observed from Fig. 2, the motors that carry the spindles androuter cutters are mounted for vertical adjustment as well as lateraladjustment on their respective carriages. This enables the constructionto be used on boards of varying thicknesses and varying widths. Forexample, with a board of greater thickness than that shown, the upperrouting cutter would be elevated. Likewise, with a board of greaterwidth than that shown both routing cutters may have to be shifted sothat the common vertical plane to which both routing cutters out will belocated centrally of the board.

From the above described construction, it will be appreciated that theimproved scarfing machine enables oppositely disposed scarfs to be cutand tongues to be formed on the end or a board or timber. Such operation,may be performed quite rapidly, and with great accuracy. If it isdesired to increase or decrease the slope of the scarfs i3 and Hi, thismay be readily accomplished by adjusting the positions, of the rails bymeans of the eye bolts 43.

Various changes may be made in the details of construction withoutdeparting from the spirit and scope of the invention as defined by theappended claims.

I claim:

1. A machine for cutting mutually opposed scarfs on an end of a woodenelement comprising a frame, a support on said frame on which the elementmay be placed, mutually divergent ways pivotally mounted in the samevertical plane on said frame adjacent the support and on opposed sidesthereof, means for altering the divergence of each of said ways relativeto the other, a router mounted for movement along each of said ways,said routers being spaced both laterally and vertically from each other,and means for advancing and retracting the router along said ways tocause them to move toward and away from the wooden element.

2. A machine for cutting mutually opposed scarfs on an end of a woodenelement comprising a frame, a support on said frame on which the elementmay be placed, a stop at the end of the support against which an end ofthe element may be positioned, ways pivotally mounted in the samevertical plane on said frame adjacent the support and on opposed sidesthereof which are mutually divergent in a direction longitudinally ofthe element, means for altering the divergence of each of said Waysrelative to to the other, a router mounted for movement along each ofsaid ways, said routers being spaced laterally and vertically from eachother, means for advancing the routers simultaneously along said ways,and means for moving the stop out of the path of the routers in advanceof the advancement of the routers into engagement with the element.

3. A machine for cutting mutually opposed scarfs on an end of a woodenelement comprising a frame, a support on said frame on which the elementmay be placed, a stop at the end of the support against which an end ofthe element may be positioned, ways pivotally mounted in the samevertical plane on said frame adjacent the support and on opposed sidesthereof which are mutually divergent in a direction longitudinally ofthe element, means for altering the divergence of each of said waysrelative to the other, a router mounted for movement along each of saidways, said routers being spaced both laterally and vertically from eachother, a hold down means engageable with the element, and

means for moving the hold down means into engagement with the elementand simultaneously moving the stop out of the path of the routers inadvance of the advancement of the routers into engagement with theelement.

4. A machine for cutting mutually opposed scarfs on an end of a woodenelement comprising a frame, a sup-port on said frame on which theelement may be placed, mutually divergent ways pivotally mounted in thesame vertical plane on said frame adjacent the support and on opposedsides thereof, means for altering the divergence of each of said waysrelative to the other, a router mounted for movement along each of saidways, said routers being spaced both laterally and vertically from eachother, and means for advancing and retracting the routers along saidways to cause them to move toward and away from the wooden element, saidways being adjustable as to inclination whereby the slopes of the scarfscut by the routers may be varied.

5. A machine for cutting mutually opposed scarfs on an end of a woodenelement comprising a frame, a support on said frame on which the elementmay be placed, means on the frame providing a ways beneath the supportextending in a direction longitudinally thereof, means on the frameproviding a second ways above the support extending in a directionlongitudinally of the support, said ways being pivotally mounted in thesame vertical plane and mutually divergent toward the support, means foraltering the divergence of each of said Ways relative to the other, acarriage movable on each of said Ways, a motor-driven router on each ofsaid carriages, said routers being spaced both laterally and verticallyfrom each other, flexible means connecting said carriages to cause thecarriages to move simultaneously toward and away from said support, andmeans for moving one of said carriages toward and away from saidsupport, said routers each having a cutter disposed one in advance ofthe other arranged to cut to the same vertical plane.

No references cited.

